The inflammatory cellular infiltrates found in human dental pulp are presumed to mediate the pathogenesis of pulpitis. However, the immunologic nature of the host responses involved in pulpal inflammation remain unclear. This proposal seeks to define, in situ, the isolate and characterize the immunoglobulins present in pulp cellular infiltrates. The first experimental approach will to quantitative characterize the histologic nature of the pulpitis cellular infiltrates and ascertain whether there is any correlation with symptomatology. To accomplish this approach serial pulp tissue sections will be examined and separately quantitated to study the random or non-random distribution of the cellular infiltrate present. The second experimental approach will use immunoperoxidase and immonofluorescent techniques to characterize and quantitate the distribution of cell-associated immunoglobulins. In addition, efforts will be made to assess whether the distribution of cell-associated immunoglobulins correlates with particular symptomatology. The third experimental approach will isolate immunoglobulins from pulp organ tissue cultures. The heavy chain class and specificity for various oral bacteria of these pulp immunoglobulins will be compared with serum immunoglobulins to see if the bacterial etiological agent(s) can be identified.